First Relationship Syndrome, also known as FRS, is the condition of being chronically attracted to the first person you enter a relationship with. Being inflicted with said syndrome makes the process of getting over this person when you break up all the more difficult. Common symptoms include constant distraction, sadness, and in more extreme cases, stalking.

Eddie can't get over Holly, so he's resorted to picking out of her garbage can. That pussy, it MUST be First Relationship Syndrome.

First Relationship Syndrome (FRS): the first 'serious' and/or long-term relationship for at least one of the parties in a relationship, leading to constant preoccupation. In many instances this will be the sufferer's first sexual relationship, though this is not always the case.

Symptoms of FRS include:
- constantly discussing partner, or bringing up their name in conversations;
- insisting that they 'cannot be apart' or 'will be together forever';
- fears/paranoia/distrust/jealousy about partner's feelings/actions (though on the other hand sufferer may be totally oblivious to signs of deceit);
- insistence that any actions of the partner are without fault. Includes fierce justification or defensiveness;
- couples or sufferers distancing themselves negatively from social circles or activities. For example, opting to stay in rather than go out "like an old married couple";
- sufferers engaging in the activities/behaviors of their partner, despite never having expressed interest in these activities before;

Long-term FRS-based relationships may deteriorate with time, however both may feel as though they are under pressure to stay committed to the relationship. Either party may be directly responsible for this pressure, but it more commonly stems from a feeling of anxiety about being alone (since they have been together so long). This most commonly occurs in couples where both parties suffered from FRS simultaneously.

Jack has just started dating Jill. They are quite happy. Since Jack has never had a relationship that has lasted this long, nor been this intimate, he considers himself in love. Jack begins to discuss Jill at every opportunity. He neglects his friends in favour of spending time with Jill, and when he does spend time with his mates, it is mostly spent talking about Jill, and relating even the most random of subjects back to her.

Jack's friends and family recognise the First Relationship Syndrome immediately, and while trying to be supportive, they warn Jack about counting his chickens before they hatch. After all, he and Jill haven't been together that long.

Jack puts a lot of pressure on Jill, unintentionally. He likes to talk with her about their future - what they will do, where they will live etc. Both Jill and Jack have changed somewhat, since they were young when they first got together and now have different interests. However Jack insists to his friends that he and Jill will be together forever, even when they drift apart. He justifies this sudden wedge between them to his friends/family. He may even blame himself.

Jack eventually moves on, and in subsequent relationships is more relaxed and mature, after identifying that his feelings for Jill were mostly FRS.